Generally speaking, various types of conventional pipe couplings for coupling and sealing adjacent pipe ends of two pipe sections include a coupling sleeve or collar with each pipe end extending into a respective end of the coupling sleeve. A gasket is held adjacent each end of the sleeve overlying the pipe section, or alternatively, along the length of the sleeve. To secure the pipe ends in place, at least one of the sleeve and the gasket(s) must be compressed onto the pipe ends to form a tightened or sealing engagement. The various types of pipe couplings available today include different types of clamping elements or mechanisms for producing this selective compression on the sleeve and/or the gasket(s).
In one example, a pipe coupling is shown in U.S. Pat. No. 6,168,210 and utilizes continuous flanges (also referred to as “glands”) that are coupled together via bolts spanning a longitudinal length of the sleeve. As described in that reference, the flanges, sleeve ends, and gaskets have particular relationships that affect the seal and allow the coupling to work over a range of pipe sizes to compress the gaskets against the pipe ends as the flanges are drawn towards each other using the bolts.
In another example, a pipe coupling is shown in U.S. Pat. No. 8,528,945 and utilizes split-ring glands that each encircle one of the sleeve ends and the gasket(s) adjacent that sleeve end. As described in that reference, the encirclement of the sleeve end and the gasket(s) is complete except at a gap formed between spaced ends of two gland members defining the split-ring gland. Instead of requiring bolts that span the longitudinal length of the sleeve, each split-ring gland can be tightened independently by using a bolt to draw together bolt flanges located on the spaced ends of the split-ring gland. Once again, the gasket(s) and split-ring glands are designed to enable a wide range of clamping force adjustment and gap size so as to engage with various sizes of pipe ends at the sleeve.
Yet another example of a pipe coupling is commercially referred to as a Straub® pipe coupling, some of which are manufactured by Swiss company Straub Werke AG and distributed by companies such as Performance Coupling Company of National City, Calif. As can be seen in product manuals on their website straub-couplings.com, at least an outermost portion of the sleeve of this type of pipe coupling may be split to define a gap that extends along the longitudinal length thereof. Thus, once the pipe ends are inserted into the opposing ends of the sleeve, this outermost portion or clamping elements secured to the outermost portion compress the gap by tightening a series of bolts extending across the gap between corresponding pairs of bolt flanges. Other types of pipe couplings are also known, many of these being secured together and adjusted in compression with some type of threaded fastener and bolt arrangement, just as in the three specific examples described above.
Consequently, many of the pipe couplings used in the field today are installed and adjusted using threaded bolts and nuts. Typically, a socket wrench or some sort of similar tool must be used to rotate the bolts to perform the installation process. However, many pipe couplings are provided with a wide range of adjustable compression that may be applied, and so the bolts may need to be moved a significant length or distance during the tightening of the pipe coupling onto the pipe ends. In addition to requiring more time and manual labor for longer movements, specialty socket wrenches must sometimes be provided to handle the long length of movement from the starting or nominal (uncompressed) position to the fully compressed and sealed engagement position. The added complexity of parts and tools for the job may be undesirable when working in the field, such as when an installer is working in dark or poor environmental conditions on a buried pipe connection.
As such, it would be desirable to further improve the various types of conventional pipe couplings to minimize the number of separate or loose parts and tools that an installer must work with when connecting two pipe ends using the pipe coupling. Furthermore, it would also be desirable to reduce the time and manual labor required to install these pipe couplings, thereby making the users more efficient overall.